OK this is strange. my fuel pump burned out (at least i think it did) so i put a new one in. so i go to start it and the new pump doesn't even turn over. i tried about 3 more times and it finally started but didn't run to well but then it got better. here is the problem, some times the fuel pump wants to run and some times it doesn't. it makes a bad moaning sound like it ran out of gas when it works, but i put 5 gallons in it and i haven't driven it anywhere. and now it can hear it pump and the engine tries to start but it wont run. its not a stock ford pump. and when i got it, the body of the motor was about half an inch longer then the stock. so it was a very tight fit getting it back into the tank. could the filter be bottoming out on the fuel tank causing it not to suck fuel? or is it a clog some place? because it ran fine for the most part of the day. i drove it down my street. but when i let it cool it ran like crap and stalled and would start. could this be an ecc problem? the truck is a 91 f150 xlt. has about 180,000 plus miles on it.

 

or could it be the fuel relay?

 

anyone?

 

Best bet would probably be to put a fuel pressure guage on it and see for sure if it's a fuel issue before going much further.

I guess in theory, the pickup screen could be bottomed out. Maybe also a faulty relay, a loose fuel line connection, faulty wiring harness (likely the section between the frame rail and the pump).

Could be a totally different tail to chase - a fuel pressure guage will give you more ideas which tail to get serious about.

 

Mine did pretty much the same thing. I dropped the tank, and heard some noise inside. It was rust swishing back and forth. Just my experience, and I don't know how rusty your tank is. I ended up having to put another pump, and fliter in it cuase the rust burned up the pump. And, I put a junkyard tank in it for 60 bucks with the sending unit.

 

i didn't hear anything when i dropped the tank. also sometimes it would sound normal and other times it would make a bad moaning sound. so it must be rust huh?

 

OK this is some very strange crap. the front fuel pump which hasn't worked in ten years just decides to work again. the rear tank is running fine now but it isn't picking up fuel so I'm thinking rust. but what makes a fuel pump work all of a sudden? do i need a new ecc?

 

Each tank has a wiring harness running from the main trunk on the driver's frame rail to the tank - they are fairly cheap to just replace with a new one, or you could inspect the length of wiring to see if there is a bad connection, frayed wire, etc. It is exposed under the truck, so you never know what could have hit, scraped, etc. on it.

I think I'd check into that before going much further.

 

do you have a fuel injected engine? maybe the pump you have doesnt give enough pressure

 

OK I've ran into another problem. what will cause the back tank to pump fuel into the front tank? because i got both tanks working and i put 10 gallons of gas in the back tank and i put 5 in the front. the back tank ran out of gas in like 10 minutes. there's know way a truck can burn through 10 gallons of gas in 10 minutes while idling in the drive way. so i checked the front tank and sure enough there was 15 gallons in the tank. i have only disconnected the back tank fuel lines and i made sure i put them back the right way and i wired the new fuel pump the right way to. is this a selector pump problem?